This invention relates to polyoxazoline and polyoxazine compounds and, in particular, those compounds having at least two pendant oxazoline or oxazine functionalities.
Compounds having two or more oxazoline rings are useful as crosslinking agents. Previously, such compounds have been prepared a number of ways, each having some limitations. Bisoxazolines have been prepared by the reaction of dicarboxylic acids with monoethanolamine. This reaction is not especially clean, and requires difficult purification procedures. Bisoxazolines have also been prepared by reaction of hydrogen sulfide with isopropenyl oxazoline. This reaction is only capable of producing bisoxazolines and, thus, is not useful in preparing higher polyoxazolines. Another method of preparing polyoxazolines is by homo- or copolymerization of isopropenyl oxazoline. This procedure is frequently unsatisfactory as it produces polyoxazolines with many pendant groups, resulting in inefficient use of the oxazoline rings in crosslinking reactions. Also, since the polyoxazoline has a high molecular weight, it is often not convenient to handle and use.
In view of the deficiencies of the prior art, it would be highly desirable to prepare, in a relatively simple and efficient manner, a compound having a plurality of oxazoline or oxazine rings.